BUENOS AIRES, Argentina — The "marker" lurks inside the bank, looking for people pulling large amounts of cash from a safe deposit box or bank account. The gunmen linger outside, usually on motorcycles, waiting to make their move.

For people like Carolina Piparo, eight months pregnant and carrying a purse full of cash for a down payment on her first home, gangs like these are an unavoidable risk in today's Argentina, where the underground cash economy is fueling a frightening new crime wave.

The July 29 attack that left Piparo comatose and killed her child added to a toll of thousands of crime victims - 4,998 reported "withdrawal robberies" in the first half of this year alone, according to Louis Vicat, a security consultant who keeps track privately because the government hasn't published detailed crime statistics since 2007.

Many victims don't even report being robbed, because they wouldn't be able to explain to tax agents where they got the money, says Vicat, who retired as deputy internal affairs chief of the Buenos Aires provincial police.

And yet cash on the table is simply the only way to do business - even when buying homes or entire companies - for many people in Argentina.

Transferring such money electronically would solve the problem in an instant. But in a society where income tax evasion runs about 50 percent and taxes eat up 65 percent of the money people do declare, many people are reluctant to use banks that way. Even people who want to pay all their taxes have a hard time complying, because there's always someone demanding to hide all or part of the transaction by paying in cash - preferably U.S. dollars.

The attack on Piparo in provincial La Plata prompted anti-crime marches and no end of fingerpointing by police and politicians. And yet a fractured Congress failed to agree to even debate a package of weak bank security proposals last week. Despite some arrests, "withdrawal robberies" continue unabated.

Piparo had saved for years with her husband to buy a home to raise their baby in. When it came time to withdraw the down payment, the teller told them the bank branch didn't have enough dollars; they would have to come back the next day.

Piparo did, with her mother, carefully putting $13,250 in her purse.

The bank's cameras recorded a burly man watching from behind them in line - a "marker" who later confessed to signaling others outside. Two men on a motorcycle stopped their car, threw Piparo to the ground and shot her in the face and chest as she begged them to just take the money. Her baby boy, Isidro, was born as she lay comatose, but didn't survive.

Piparo is now slowly recovering and seven people have been arrested, but many Argentines remain furious that they are exposed to such risks.

Politicians, economists, security experts and others interviewed by The Associated Press say one of the root causes of the robberies is Argentina's undeclared economy, along with the widespread reluctance of people to use a bureaucratic and costly banking system.

Add inflation of 25 percent or more this year, and people have many reasons to avoid transferring money from one account to another.

Soccer player Fabian Cubero lost a huge sum last month when his accountant left a bank with cash and was attacked by two criminals on a motorcycle in the parking garage. The player wouldn't say publicly just how the robbers got, but several newspapers reported it was 600,000 pesos - $150,000.

"These things happen on a daily basis. One has to get used to being robbed and be thankful for not getting killed," Cubero said.

Argentines aren't obligated to file tax returns each year unless they declare an annual income of least 144,000 pesos ($36,000) - and only 20 percent of the people officially meet this threshold. Many people handle as many transactions as possible in ways that avoid the scrutiny of tax agents.

With income tax compliance so low, the government seeks revenue in many other ways, imposing a 21 percent sales tax, bank transaction taxes, a "stamp tax" on business contracts, an annual "wealth tax" on personal property and many fees based on the declared value of a person's home.

"Of every 100 pesos you make, 65 you owe to the state through various taxes. That is why there is so much of this underground economy," said Ponciano Vivanco, a veteran notary in Buenos Aires who estimates that 90 percent of Buenos Aires' real estate is purchased in cash.

Argentina also taxes money transfers, check deposits and withdrawals and other routine banking transactions. Banks add their own fees and rules to discourage customers from using rival banks or credit cards.

"There are big Argentine companies that keep an important part of their management off the books. This also is common with small and medium enterprises. Anything you want to buy, you don't get an official receipt for it," economist Marcelo de Las Carreras said.

Still another factor that leads many Argentines to rely on cash is a mistrust of the country's currency.

Argentines can't forget the 2001 economic crisis that forced the government to devalue the peso, robbing most people of two-thirds or more of their wealth overnight. Banks were ordered to freeze deposits, and dollar-denominated savings could be withdrawn only in devalued pesos.

"Banks swindled us not long ago," Vivanco, the notary, said. "People who had their deposits in dollars were given back pesos and many lost 70 percent of their savings, and they blame the financial entities for this, even though the banks were just following the government's orders."

Many people avoid peso-denominated bank accounts, and convert their pesos into dollars that they stash in safe deposit boxes. Or they spend their cash on the likes of cars, appliances and apartments in hopes of protecting their wealth.

"The big money is kept in safe deposit boxes, not in bank accounts," said Congressman Federico Pinedo, who is working on reforms that could make banking less expensive and bureaucratic.

Meanwhile, even the Piparo case has generated little more than outrage and empty promises so far. Some lawmakers propose requiring additional security cameras, privacy walls in teller lines and cell phone blocking technology inside bank branches. But even those proposals were shelved in Congress last week, as various factions sought political advantage ahead of the 2011 presidential elections.

"It's the same as ever: When they have to show up on television they appear all suntanned with their team of beauticians, but when they have to work nothing ever happens," Piparo's husband, Juan Ignacio Buzzali, angrily told Channel 13.